915 gearbox, Type 4 engine and 228mm WBX FW

[Sandeep]

I have mocked up the 915 with a spare T4 case, crank and 228mm wbx flywheel. The measurements from the edge of the bellhousing on the 915 to the ring gear of the 228mm FW are identical to the same setup on my 901 gearbox ! The 228mm PP fits with no clearancing issues either.

I am thinking I can just use the stock 901/914 starter and all will be well. I will hook up the starter tonight with a battery and see if it engages like I think it will.

The only issue remaining then would be the clutch engagement, I think easily fixed by using the BAFS TOB sleeve and T3 TOB for a push clutch and then a hydraulic slave to actuate.

Seems simple

Sandeep

[Sandeep]

I measured the engagement of the stock 901/914 starter last night and it extends 0.5" (12.7mm). The starter spins the 228mm flywheel when mated to the 915 box, but I am only engaging 0.118" (3.0mm) into the ring gear.

It works, but I can see it wearing out in short order.

I will try the IMI-101 starter as suggested by Tomac.

Sandeep

[Wally]

Originally Posted by Sandeep

The only issue remaining then would be the clutch engagement, I think easily fixed by using the BAFS TOB sleeve and T3 TOB for a push clutch and then a hydraulic slave to actuate.

Seems simple

Sandeep

yeah, the 'only' issue...
BTW, Whats a BAFS??
The most elegant solution would be a annular hydraulic TOB imho, but what, which and how?
I have heard/seen an annular one from a vw passat made to work on a 901, but somebody pls find one that works on a 915. That would be awesome!

[wrenchnride247]

Originally Posted by Sandeep

The only issue remaining then would be the clutch engagement, I think easily fixed by using the BAFS TOB sleeve and T3 TOB for a push clutch and then a hydraulic slave to actuate.


Sandeep

BAFS...Bug@5speed Wally TOB sleeve (or guidance tube as Martin calls it) Very nice machine work too!

[Wally]

Sandeep,
Did you already try to slip in a 915 disk between that 228mm type 4 flywheel and your 228mm type 4 pressure plate?

I have tried a new (!) LUK 228mm pp I bought for the occasion and also wanted to use Martins guidance tube, but I had the first batch that did'n't fit in the 915... After I had it machined some more, it probably will fit now.

The new LUK pp and the 915 disk would not fit . After consulting with Martin how this is possible, he got back to me explaining there are probably two versions of pp's and only one fits...
Recently I got another (used) 228mm PP from Fichtel & Sachs and that did not fit immediately either, but due to the different construction of these, with some clearencing of the pp and a bit of the disk, the 915 disk now spins freely in the 228mm F&S pp!

So if you want to go this route, I suggest to at least go with a F&S pp or get the Alfa 164 disk Tom mentioned earlier

Any reports on annular trow-out bearings that will work on a 915 box and are small enough to fit between there and the 228mm PP, are greatly welcomed

Regards,
Walter

[Sandeep]

Wally,

Thanks for the information. I have not tried the 915 clutch yet because I have not ordered it. I am looking at a custom disc, either from kennedy (6 puc solid) or from a local porsche tuning shop. I need to use my kennedy stage 2 228mm PP and will take the fw / PP to the porsche shop and see what we can come up with. If no solution can be found, I may have to try the F&S as suggested.

I still have not ordered the hydraulic clutch kit either. Are you happy with your setup -> clutch pedal acctuation ? I can sort out the slave cylinder.

Sandeep

[Wally]

Originally Posted by Sandeep

I still have not ordered the hydraulic clutch kit either. Are you happy with your setup -> clutch pedal acctuation ?
Sandeep

At the moment, yes, very! Even tho the stock 915 pp is very heavy, when you have exactly the right pivot point length of the clutch arm where you hook the slave onto, your good.
Since the 915 needs a longer throw I heard, I originally used a smaller pivot length and pedal pressure was too high for my taste. After I lengthenend the pivot arm, I can still clutch the disk free and all is good
That took some time and wrenching tho... and I should really let it be for now

[Sandeep]

Cool !

Are you using the SACO kit or the Aircooled.net kit ? Are they the same ?

I've almost got the 915 box mounted in the chassis, now need to sort out the clutch.

Thanks

Sandeep

[dub_crazee]

thanks for the replies

[wrenchnride247]

Here is an update on 228mm flywheels and 915's from Kennedy Eng. I have talked with Brett at Kennedy, and got some info on the different ring gear placement. A 228mm late bus flywheel's ring gear is .250in. short (as sandeep found out) when used in a 915, and a 914 flywheel is only .020in. shorter. The 6cyl.911/915 flywheel doesn't have a ring gear on it, instead it is bolted to the PP.(one reason the other flywheels come up short) These dimension's are measured from the stock 915 starter gear engagement point. Kennedy's conversion flywheel for a 915 to T4 uses ALL the 915 parts (disc, PP, ring gear, and TOB) these are very expensive parts. I have spent too much money on Porsche parts already.

Now for the good news! I explained what I wanted to do with my T4 to 915 conversion, and they said no problem. So, they are making me a forged billet 915 to T4 conversion flywheel that will have the ring gear on the flywheel, and will use VW bus 228mm PP's, disc's, and TOB (with one of Martin's guidance tube's) . The 228mm disc will just have a 915 center hub on it (I think Wally got one of these disc's) Of course with this set-up it will now be a "push type" clutch.

[dub_crazee]

martin at Bug@5 does a starter that will mesh with the bus 228mm flywheel which is what i am planning on using -

my set up will be

bug@5 starter
bug@5 guidance tube
T3 TOB
228 Bus flywheel
228 PP

not sure on friction plate just yet....

[wrenchnride247]

Originally Posted by dub_crazee

martin at Bug@5 does a starter that will mesh with the bus 228mm flywheel which is what i am planning on using -

my set up will be

bug@5 starter
bug@5 guidance tube
T3 TOB
228 Bus flywheel
228 PP

not sure on friction plate just yet....

Sounds like a plan. When I got my parts from Martin he didn't have a starter from what I remember...been two years now (where has the time gone)

Anyway, With my engine size and projected power output Jake didn't want to trust a cast 228 flywheel thats over twenty years old. I know lots of people use them, but we felt it would be the weak link in this setup. If you want a new forged billet 228...Kennedy can make one. For the past two years Jake and I have tried to find a factory forged 228, but never found one. The ones people said were forged that Jake bought were cast. And the companies we talked to that specialize in WBX motors said they never seen one either.

[Wally]

My 228mm that now runs 350 hp/6500 rpm is cast too and obviously holds fine, but I'd rather have the Kennedy 228mm steel one as well tbh. Its not forged billet BTW, I asked specifically and they say its just a very good steel item, which is a sort of chr-mo if your not picky ;-). Pity it costs so much to ship these have items to europe.

[DORIGTT]

What's the projected cost of that soon to be beautiful flywheel?

[wrenchnride247]

Originally Posted by DORIGTT

What's the projected cost of that soon to be beautiful flywheel?

I don't know the exact amount (didn't ask) yet, reguardless...I need it!
My guess though is about $250?